Substantially non-toxic biologically active mucosal adjuvants in vertebrate subjects

ABSTRACT

A method of eliciting an immune response against an antigen in a vertebrate subject, the method comprising the steps of providing an antigen-adjuvant composition comprising the antigen and a substantially non-toxic adjuvant molecule having biological activity in mucosal tissues, and administering said antigen-adjuvant composition to the vertebrate subject in a manner such that initial contact occurs in mucosal tissue of the vertebrate subject, whereby an immune response is elicited. Cytokines are preferred adjuvants. Preferred cytokines are interleukin-1α(IL-1α) and interleukin-1β (IL-1β).

CROSS REFERENCE TO RELATED APPLICATION

This application is a divisional of U.S. patent application Ser. No. 09/168,910, filed Oct. 8, 1998,now U.S. Pat. No. 6,270,858, the entire contents of which are herein incorporated by reference.

GRANT STATEMENT

This work was supported by National Institute of Health (NIH) grant 5 U01 A135351-04. The United States Government has certain rights in the invention.

TABLE OF ABBREVIATIONS

-   -   CT—cholera toxin     -   CTL—cytotoxic T lymphocyte(s)     -   DC—dendritic cells     -   DTH—delayed-type hypersensitivity     -   EGF—epithelial growth factor     -   FKN—fractalkine     -   GALT—gut-associated lymphoid tissue     -   GCSF—granulocyte colony stimulating factor     -   GM-CSF—granulocyte-macrophage colony stimulating factor     -   HIV—human immunodeficiency virus     -   HSV—herpes simplex virus     -   IDC—immature dendritic cells     -   IFN—interferon     -   lg—immunoglobulin     -   lgA—immunoglobulin A     -   IGF-1—insulin-like growth factor     -   lgG—immunoglobulin G     -   lL—interleukin     -   LARC—liver and activation regulated chemokine     -   LT—heat-labile toxin     -   MDC—macrophage derived chemokine     -   PARC—pulmonary and activation regulated chemokine     -   PT—pertussis toxin     -   RSV—respiratory syncytial virus     -   SLC—secondary lymphoid-tissue chemokine     -   TARC—thymus and activation regulated chemokine     -   TGF—transforming growth factor     -   Th 1—T helper cell type 1     -   Th 2—T helper cell type 2     -   TNF—tumor necrosis factor     -   TT—tetanus toxoid

TECHNICAL FIELD

The present invention relates to the use of substantially non-toxic, biologically active molecules as mucosal adjuvants in vertebrate subjects. More particularly, the present invention relates to the use of cytokines, such as interleukin-1α (IL-1α) and interleukin-1β (IL-1β), as mucosal adjuvants in vertebrate subjects.

BACKGROUND ART

Antigen-specific mucosal immune responses, such as secretory lgA production and mucosal cytotoxic T lymphocyte (CTL) responses, may play an important role in host protection against infectious agents that infect via the mucosal surfaces of the host, including human immunodeficiency virus (HIV), herpes simplex virus (HSV), respiratory syncytial virus (RSV), Bordetella pertussis, and Salmonella typhimurium. See Ogra, in Mucosal Vaccines. p. 3 (1996).

A major obstacle in the path of developing effective mucosal vaccines is the identification of a safe and effective mucosal adjuvant. Indeed, mucosal immunization with soluble protein or peptide immunogens in the absence of a mucosal adjuvant tends to induce a state of antigen-specific immunological tolerance known as oral tolerance, or more appropriately, mucosally-induced tolerance. See e.g., Mowat, in Handbook of Mucosal Immunology. p. 185 (1994); Husby et al., Journal of Immunology 152:4663 (1994); Staines et al., Clinical & Experimental Immunology 103:368 (1996).

In contrast, mucosal immunization with soluble protein antigens or peptides co-administered with a mucosal adjuvant such as cholera toxin (CT), pertussis toxin (PT), or heat-labile toxin (LT) may induce potent systemic and mucosal, humoral and cell-mediated immune responses. Indeed, the most potent and best-studied mucosal adjuvant is cholera toxin (CT), Elson et al., in Handbook of Mucosal Immunology, p. 391 (1994). However, CT is likely unsafe for use as a mucosal adjuvant in humans because as little as 5 micrograms (μg) of CT causes massive diarrhea when intragastrically administered to human volunteers. Levine et al., Microbiological Reviews 47:510 (1983). Moreover, in some cases the use of CT as a mucosal adjuvant in research animals has been associated with the production of antigen-specific lgE responses and lethal anaphylactic reactions. See e.g., Snider et al., J Immunol 153:647 (1994); Marinaro et al., J Immunol 155:4621 (1995).

To repress the toxicity associated with toxin adjuvants, mutant CT, LT, and PT molecules have been produced that exhibit reduced or undetectable toxic activity while maintaining mucosal adjuvant activity. O'Hagan, Joumal of Pharmacy and Pharmacology49:1 (1997). Although these molecules possess potent adjuvant activity with reduced toxicity, they maintain immunogenic properties when administered to experimental animals. See e.g., Douce et al., Infection & Immunity 65:2821 (1997). Thus, the immunogenicity of these mutant toxin molecules also prevents their widespread and repeated use as mucosal adjuvants in that pre-existing immunity to CT reduces their adjuvant activity. Wu et al., Vaccine 12:215 (1994).

PCT Publication No. WO 91/01143 to Pillai et al. describes intedeukin (IL)-containing vaccine compositions which comprise a mixture of antigen and an adjuvant amount of an IL adsorbed onto a mineral in suspension, and a preservative. The mineral is described as preferably being alum. Alum is described as stabilizing the biological activity of the IL. Exemplary IL's includes IL-1α, IL-1β, IL-2, IL-3, IL-4, IL-5, IL-6 and IL-7. It is noted that in the absence of alum, IL's have short half lives. Carbohydrate-containing units found uniquely on cancer cells or found associated with allergens are particularly described antigens. However, the problems associated with oral or mucosally-induced tolerance of antigens are not addressed.

U.S. Pat. No. 5,334,379 issued to Pillai et al. on Aug. 2, 1994 describes cytokine and hormone carriers for conjugate vaccines. The antigens described in this patent are bound or genetically fused with a cytokine, lymphokine, hormone or growth factor having immunomodulating activity. Particularly contemplated antigens include the carbohydrate-containing antigens often present in bacteria. Exemplary cytokines, lymphokines and hormones include IL-1α, IL-1β, IL-2, prolactin, EGF, TGF, GM-CSF, GCSF, IGF-1, somatotropin, or insulin. The conjugates may be prepared by any of the known complex, biologically compatible methods for coupling carbohydrate-containing antigens or other antigens to carriers. Covalent coupling is described as a preferred method. Indeed, Examples 1 and 2 describe the elaborate reactions required to conjugate or bind the antigens to the cytokine, lymphokine, hormone or growth factor. However, the problems associated with oral or mucosally-induced tolerance of antigens are not addressed.

A recent review article by Kramer et al. entitled “Cytokine Mediated Effects in Mucosal Immunology” in Immunology & Cell Biology 73:389 (1995) discusses the role of IL-5, IL-6, and TGF-β in the induction of mucosal lgA responses. Particularly, this paper discusses published results from experiments done in mice lacking a functional IL-5 or IL-6 gene. It also discusses papers which describe the co-expression of IL-5 or IL-6 with vaccine antigen in a live vaccinia virus, and which describe that the co-expression of IL-5 or IL-6 enhances mucosal lgA responses. However, the article then suggests that complex delivery methods will be required to deliver the cytokines to the mucosa.

Another recent review article by O'Hagan entitled “Recent Advances in Vaccine Adjuvants for Systemic and Mucosal Adjuvants” in the Journal of Pharmacy and Pharmacology 49:1 (1997) discusses the state of the use of adjuvants for systemic and mucosal administration. This review article discusses a number of different adjuvants for use with mucosally administered vaccines including particulates (i.e. microspheres), oil-in-water emulsions, and mutated forms of heat-labile enterotoxin (LT) and cholera toxin (CT). But, this article does not mention the use of cytokines as mucosal vaccine adjuvants.

A journal article by Lin et al. entitled “Present Status of the Use of Cytokines as Adjuvants with Vaccines to Protect Against Infectious Diseases” in Clinical Infectious Diseases 21:1439 (1995) discusses the use of select cytokines (IL-1, IL-2, IL-3, IL-4, IL-6, IL-7, and IL-12; tumor necrosis factor (TNF); interferon; and GM-CSF as adjuvants. But, the use of cytokines as mucosal vaccine adjuvants is not suggested in this article.

A journal article by Nash et al. entitled “Recombinant Cytokines as Immunological Adjuvants”, Immunology and Cell Biology 71:367 (1993) discusses the use of recombinant ovine IL-2, IL-1α and tumor necrosis factor-α (TNF-α) as adjuvants. The formulation of IL-1α with aluminum hydroxide (alum) is mentioned for use as an adjuvant capable of enhancing secondary humoral responses. But, there is no suggestion of mucosal administration of IL-1α.

Despite the substantially non-toxic and biologically active nature of cytokines like the interleukins, the recognized uses of such molecules as adjuvants require complex conjugation or formulation techniques. Moreover, even in view of the potential benefits of mucosal immunization, a solution to the oral tolerance problem described above has yet to be identified. Thus, a safe, effective and easily formulated mucosal adjuvant is needed to aid the development of effective mucosal vaccines.

SUMMARY OF THE INVENTION

In accordance with the present invention, a method of eliciting an immune response against an antigen in a vertebrate subject is provided. The method comprises the steps of providing an antigen-adjuvant composition comprising the antigen and a substantially non-toxic adjuvant molecule or molecules having biological activity in mucosal tissues, and administering said antigen-adjuvant composition to the vertebrate subject in a manner such that initial contact occurs in mucosal tissue of the vertebrate subject, whereby an immune response is elicited. Preferably, the immune response comprises a systemic and/or mucosal immune response.

Accordingly, it is an object of the present invention to provide a functional method of mucosal immunization.

It is another object of the present invention to address oral tolerance in mucosal immunization by providing a safe and effective mucosal adjuvant.

It is still another object of the present invention to provide a mucosal adjuvant that is easily formulated yet substantially non-toxic to the subject to be immunized.

Some of the objects of the invention having been stated hereinabove, other objects will become evident as the description proceeds, when taken in connection with the accompanying drawings as best described hereinbelow.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a bar graph depicting serum antigen-specific lgG end-point titers (reciprocal) after intranasal immunization as indicated in Table 2. #=experiment #1; #2 =experiment #2; #3=experiment #3. Results for experiment #1 represent day 42 serum. Results for experiments #2 and #3 represent day 21 serum. There were three to four (3-4) mice per group per experiment. a=significantly greater than “none” control (p<0.05).

FIG. 2 is a bar graph depicting vaginal antigen-specific lgA end-point titers (reciprocal) after intranasal immunization as indicated in Table 2. There were three to four (3-4) mice per group, per experiment. #1 =experiment #1; #2 =experiment #2; #3=experiment #3. Results for experiment #1 represent day 42 samples while experiments #2 and #3 represent day 23 vaginal lavage samples. Solid bars=lgA; open bars=lgG. Vaginal lavage samples were pooled for each group.

FIG. 3 is a bar graph depicting antigen-specific DTH ear swelling responses after intranasal immunization as indicated in Table 2. There were three to four (3-4) mice per group, per experiment. #1 =experiment #1; #2=experiment #2; #3=experiment #3. Results for experiment #1, #2, and #3 represent day 43, 49 and 35 ear swelling responses respectively. a=significantly greater than “none” control (p<0.05). b=significantly greater than none, CT×3, CT×1, IL-lα×1, and IL-1β×1 groups.

FIG. 4 is a bar graph depicting antigen-specific lymphocyte proliferative responses in splenocytes from animals immunized as indicated in Table 2. Splenocytes were harvested on day 56 for experiments #2 and #3. Solid boxes represent counts per minute for splenocytes cultured in culture media only while the open boxes represent counts per minute for splenocytes cultured in the presence of tetanus toxoid at 0.1 μg/ml. Splenocytes from three to four (3-4) mice were pooled per group.

DETAILED DESCRIPTION OF THE INVENTION

In accordance with the present invention, a method of eliciting an immune response against an antigen in a vertebrate subject is provided. The method comprises the steps of providing an antigen-adjuvant composition comprising the antigen and a substantially non-toxic, biologically active adjuvant molecule having adjuvant and other biological activity in mucosal tissues, and administering said antigen-adjuvant composition to the vertebrate subject in a manner such that initial contact occurs in mucosal tissue of the vertebrate subject, whereby an immune response is elicited. Mucosal immunization with soluble protein antigen alone induces antigen-specific (oral) tolerance while mucosal immunization with antigen in the presence of a mucosal adjuvant according to the present invention induces antigen-specific systemic and mucosal humoral and cell-mediated immune responses. Thus, the present invention addresses the problem of mucosal, or oral, antigen-specific tolerance.

While the following terms are believed to have well defined meanings in the art, the following definitions are set forth to facilitate explanation of the invention.

The term “immune system” includes all the cells, tissues, systems, structures and processes, including non-specific and specific categories, that provide a defense against “non-self” molecules, including potential pathogens, in a vertebrate subject.

As is well known in the art, the non-specific immune system includes phagocytositic cells such as neutrophils, monocytes, tissue macrophages, Kupffer cells, alveolar macrophages, dendritic cells and microglia. The specific immune system refers to the cells and other structures that impart specific immunity within a host. Included among these cells are the lymphocytes, particularly the B cell lymphocytes and the T cell lymphocytes. These cells also include natural killer (NK) cells. Additionally, antibody-producing cells, like B lymphocytes, and the antibodies produced by the antibody-producing cells are also included within the term “immune system”.

The term “substantially non-toxic” is meant to refer to adjuvant molecules which cause few detrimental effects when administered to a vertebrate subject. Examples of detrimental effects include the nausea and anaphylactic shock observed through the use of standard adjuvants like cholera toxin. Thus, the term “substantially non-toxic” can be quantified by comparison to cholera toxin as a known standard. Further, “substantially non-toxic” can mean without prolonged or major side effects including weight loss and prolonged fever, and including, but not limited to, the flu-like symptoms such as fever, prolonged muscle or joint pain, or hypotension (shock), that are observed with some vaccinations currently used in the art.

By way of further explanation of the term “substantially non-toxic” as used in accordance with the present invention, two of the adjuvants described herein below, IL-1α and IL-1β, have both been used in Phase I/II clinical trials in humans. For these human trials, IL-1α and IL-1β were used in cancer patients undergoing chemotherapy. The IL-1 was usually administered by IV drip on a daily basis. The IL-1 was found to have side effects that included flu-like symptoms, including: fever, chills and rigors, nausea, vomiting, fatigue, headache, myalgia and arthralgia, hypotension, tachycardia, abdominal pain, peripheral vein phlebitis, confusion and somnolence, dyspnea, edema and prerenal axotemia. See e.g., Veltri et al., Stem Cells 14:164-176 (1996); Rinehart et al., Can. Invest. 15:403-410 (1997); Verschraegen et al., Eur. J. Can. 32A:1609-1611 (1996); Janik et al., J. Nat. Can. lnst. 88:44-49 (1996); Weisdorf et al., Blood 84:2044-2049 (1994).

While applicants do not wish to be bound to any particular theory of operation of the invention, it is believed that many of the side effects are due to IV administration and exposure of the entire body to IL-1. Thus, applicants contemplate that intramucosal (e.q. nasal) administration of the cytokines limits systemic toxicity because the cytokines, as well as other adjuvants as described herein, are administered locally. Also, as described herein below, in mice, when using a “high” dose of IL-1 (e.g., 4 μg for 3 doses at weekly intervals), obvious toxic effects such as ruffled fur or obvious weight loss in the mice were not observed. In other studies in rabbits, which are also referred to below, nasal administration of 80 μg of IL-1β induced a 1.0-1.5° C. fever by 3-4 hours after nasal administration. But, the body temperature returned to normal within 24 hours and no weight loss was observed. Thus, the term “substantially non-toxic” is also meant to encompass the observed absence of systemic toxicity when the adjuvants of the present invention are administered intramucosally as compared to the systemic toxicity observed when contemplated adjuvants of the present invention are administered intravenously as a component of chemotherapy as described above.

The terms “mucosal administration” and “intramucosal administration” are meant to refer to a mode of administration whereby an antigen-adjuvant composition according to the present invention is administered in a manner such that initial contact occurs in mucosal tissue of the vertebrate subject. Examples of mucosal tissue include the nasal membranes, vaginal membranes, rectal membranes and gastric membranes. Thus, contemplated. administration techniques according to the methods of the present invention include intranasal administration, intravaginal administration and intrarectal administration, among other intramucosal administration techniques.

The term “biological activity” is meant to refer to a molecule having a biological or physiological effect in a vertebrate subject. Adjuvant activity is an example of a biological activity. Activating or inducing production of other biological molecules having adjuvant activity is also a contemplated biological activity.

The term “adjuvant activity” is meant to refer to a molecule having the ability to enhance or otherwise modulate the response of a vertebrate subject's immune system to an antigen.

The term “immune response” is meant to refer to any response to an antigen or antigenic determinant bythe immune system of a vertebrate subject. Exemplary immune responses include humoral immune responses (e.g. production of antigen-specific antibodies) and cell-mediated immune responses (e.g. lymphocyte proliferation), as defined herein below.

The term “systemic immune response” is meant to refer to an immune response in the lymph node-, spleen-, or gut-associated lymphoid tissues wherein cells, such as B lymphocytes, of the immune system are developed. For example, a systemic immune response can comprises the production of serum lgG's. Further, systemic immune response refers to antigen-specific antibodies circulating in the blood stream and antigen-specific cells in lymphoid tissue in systemic compartments such as the spleen and lymph nodes. In contrast, the gut-associated lymphoid tissue (GALT) is a component of the mucosal immune system since antigen-specific cells that respond to gut antigens/pathogens are induced and detectable in the GALT.

The term “mucosal immune response” is meant to refer to an immune response in the mucosal tissues of a vertebrate subject. The mucosal immune response can comprise production of lgA's, particularly secretory lgA's, in mucosal tissue at a location in the vertebrate subject away from the site of mucosal administration of the antigen-adjuvant composition according to the present invention.

The terms “humoral immunity” or “humoral immune response” are meant to refer to the form of acquired immunity in which antibody molecules are secreted in response to antigenic simulation.

The terms “cell-mediated immunity” and “cell-mediated immune response” are meant to refer to the immunological defense provided by lymphocytes, such as that defense provided by T cell lymphocytes when they come into close proximity to their victim cells. A cell-mediated immune response also comprises lymphocyte proliferation. When “lymphocyte proliferation” is measured, the ability of lymphocytes to proliferate in response to specific antigen is measured. Lymphocyte proliferation is meant to refer to B cell, T-helper cell or CTL cell proliferation.

The term “CTL response” is meant to refer to the ability of an antigen-specific cell to lyse and kill a cell expressing the specific antigen. Standard, art-recognized CTL assays are performed to measure CTL activity.

Following long-standing patent law convention, the terms “a” and “an” mean “one or more” when used in this application, including the claims.

In accordance with the present invention, the adjuvant may optionally be selected from the group including, but not limited to, cytokines, chemokines, growth factors, angiogenic factors, apoptosis inhibitors, and combinations thereof. When a cytokine is chosen as an adjuvant, the cytokine may be selected from the group including, but not limited to, interleukins including IL-1, IL-1α, IL-1β, IL-2, IL-5, IL-6, IL-12, IL-15 and IL-18; transforming growth factor-beta (TGFβ); granulocyte macrophage colony stimulating factor (GM-CSF); interferon-gamma (IFNα); or other cytokine which has adjuvant activity.

Combinations of cytokines are also contemplated for use in accordance with the methods of the present invention, as presented in the Examples below. Additionally, a particularly contemplated embodiment comprises the use of IL-12 and IL-18 in combination as a mucosal adjuvant in accordance with the methods of the present invention. When cytokines are used in combination, contemplated dosage ranges comprise about 0.3 μg/ml to about 50 μg/ml, with respect to each cytokine. Additional contemplated dosages ranges are described below.

Portions of cytokines, or muteins or mimics of cytokines (or combinations thereof), having adjuvant activity or other biological activity can also be used in the methods of the present invention.

When a chemokine is chosen as an adjuvant, the chemokine may optionally be selected from a group including, but not limited to, LARC, PARC, MDC, TARC, SLC and FKN. When an apoptosis inhibitor is chosen as an adjuvant, the apoptosis inhibitor may optionally be selected from the group including, but not limited to, toso, inhibitors of caspase-8, and combinations thereof. When an angiogenic factor is chosen as an adjuvant, the angiogenic factor may optionally be selected from the group including, but not limited to, a basic fibroblast growth factor (FGF), a vascular endothelial growth factor (VEGF), a hyaluronan (HA) fragment, and combinations thereof. Indeed, plus (+) and minus(−) angiogenic factors may be chosen as adjuvants.

Other examples of substantially non-toxic, biologically active mucosal adjuvants of the present invention include hormones, growth factors, or biologically active portions thereof. Such hormones, growth factors, or biologically active portions thereof can be of human, bovine, porcine, ovine, canine, feline, equine, or avian origin, for example, and can be tumor necrosis factor (TNF), prolactin, epidermal growth factor (EGF), granulocyte colony stimulating factor (GCSF), insulin-like growth factor (IGF-1), somatotropin (growth hormone) or insulin, or any other hormone or growth factor whose receptor is expressed on cells of the immune system.

Cytokines, chemokines, growth factors, angiogenic factors, apoptosis inhibitors and hormones can be obtained from any suitable source. They can be produced by recombinant DNA methodology. For example, the genes encoding several human interleukins have been cloned and expressed in a variety of host systems, permitting the production of large quantities of pure human interleukin. Further, certain T lymphocyte lines produce high levels of interleukin, thus providing a source of the cytokine.

The antigen-adjuvant compositions are preferably administered in a pharmaceutically acceptable vehicle. The preferred vehicle is physiological saline; but, distilled water may also be used as a vehicle. More preferably, the antigen-adjuvant composition is free of mineral adjuvants, preservatives or stabilizers, such as alum. Also preferably, the antigen-adjuvant composition is not conjugated. Rather, the antigen and adjuvant are simply dissolved and/or suspended in the vehicle.

In accordance with the present invention, antigen is intramucosally administered in combination with a substantially non-toxic, biologically active adjuvant preferably at weekly or biweekly intervals for a total of three (3) immunizations in order to stimulate a “protective” immune response. A protective immune response is an immune response sufficient to protect the immunized organism against toxic products of bacteria (tetanus toxin, cholera toxin, E. coli labile toxin, diphtheria toxin, pertussis toxin) as well as against productive infection by a particular pathogen or pathogens to which the vaccine is directed.

Stated differently, the antigen-adjuvant composition may optionally be administered once a week over a period of one to three weeks or once every two weeks over a period of two to six weeks. Alternatively, the antigen-adjuvant composition may be administered once during a first week, and then antigen only may be administered as a booster immunization once a week over a period of one to two weeks following the first week. Further, the antigen-adjuvant composition may optionally be administered once during a first biweekly period, and then antigen only may be administered as a booster immunization once every two weeks over a period of two to four weeks following the first biweekly period.

For example, IL-1α or IL-1β function as mucosal adjuvants when co-administered with antigen during the first immunization. When using IL-1α or IL-1β as a mucosal adjuvant, two additional booster immunization with antigen only sufficiently bolstered the desired level of immune response. The IL-1α or IL-1β adjuvants are preferably present in the antigen-adjuvant composition in an amount ranging from about 10 to about 1000 micrograms per kilogram body weight of the vertebrate subject. More preferably, the IL-1α or IL-1β adjuvant is present in the antigen-adjuvant composition in an amount ranging from about 50 to about 500 micrograms per kilogram body weight of the vertebrate subject. Even more preferably, the IL-1α or IL-1β adjuvant is present in the antigen-adjuvant composition in an amount ranging from about 60 to about 200 micrograms per kilogram body weight of the vertebrate subject.

Optionally, the IL-1β, may comprise recombinant IL-1β. In such a case, the recombinant IL-1β may optionally be present in an amount ranging from about 1 to about 100 milligrams per kilogram body weight of the vertebrate subject. More preferably, the recombinant IL-1β is present in the antigen-adjuvant composition in an amount ranging from about 5 to about 50 milligrams per kilogram body weight of the vertebrate subject. Even more preferably, the recombinant IL-1β, is present in the antigen-adjuvant composition in an amount ranging from about 10 to about 20 milligrams per kilogram body weight of the vertebrate subject.

The amount of adjuvant employed in the methods of the present invention will vary depending upon the identity of the antigen employed. Adjustment and manipulation of the adjuvant dosage ranges described above for adaptation to a variety of antigens is within the ability of those skilled in the art. The adjuvant-antigen compositions, or vaccines, of the present invention are intended for use in the treatment of vertebrate subjects, including both immature and adult warm-blooded animals. Exemplary warm blooded vertebrate subjects include mammals and birds. Mammals are preferred subjects, with humans comprising a most preferred subject. Indeed, in accordance with the present invention, any vaccine against infection wherein protection at mucosal sites is needed can be formulated for administration to humans or other warm blooded vertebrate animals. Further, the use of the present methods is not limited to prophylactic applications; therapeutic applications are also contemplated (e.g., AIDS prophylaxis and therapy), as well as immune focusing to alter growth, productivity or reproduction.

Certain types of immune responses are more readily produced in accordance with the methods of the present invention as compared to prior art methods. For example, a preferred systemic immune response according to the present invention comprises the production of antigen-specific lgG's at a titer of at least about 1:10,000, with a more preferred titer comprising at least about 1:20,000. As would be apparent to one having ordinary skill in the art, a titer of at least about 1:10,000 or a titer of at least about 1:20,000, for example, means that there remains a detectable quantity of antigen-specific antibody (or lg) in an ELISA assay after preparing a 1:10,000 dilution, or 1:20,000 dilution, of a sample, respectively.

A preferred mucosal immune response according to the present invention comprises production of lgA's in mucosal tissue in the vertebrate subject at a site removed from the site of administration of the adjuvant. Indeed, as set forth in the Examples presented herein below, without the administration of an adjuvant in accordance with the present invention, no mucosal lgA responses are typically observed in a subject. Moreover, for some antigens administered in accordance with methods of the present invention, the antigen-specific lgA's are produced at a titer of at least about 1:100. Additionally, for other antigens administered in accordance with methods of the present invention, the antigen-specific lgA's are produced at a titer of at least about 1:500. As would be apparent to one having ordinary skill in the art, a titer of at least about 1:100 or a titer of at least about 1:500, for example, means that there remains a detectable quantity of antigen-specific antibody (or lg) in an ELISA assay after preparing a 1:100 dilution or 1:500 dilution of a sample, respectively.

A particularly desired cell-mediated immune response comprises lymphocyte proliferation. More particularly, the desired lymphocyte proliferation is further characterized by at least about a ten (10)-fold increase in lymphocytes as compared to an unimmunized state. Even more particularly, lymphocyte proliferation is further characterized by at least about a fifty (50)-fold increase in lymphocytes as compared to an unimmunized state.

IL-1α and lL-1β are preferred examples of the mucosal adjuvants of the present invention. IL-1α and IL-1β serve as adjuvants for a variety of immune responses, including: antigen-specific serum lgG, vaginal lgA, systemic delayed-type hypersensitivity (DTH) responses, and lymphocyte proliferative responses, in cells isolated from the spleen. Indeed, the data presented hereinbelow indicates that the cytokines act as adjuvants to enhance 1) antigen-specific antibody (systemic lgG, mucosal lgA) and 2) cell-mediated immunity by lymphocyte proliferation and delayed-type hypersensitivity (DTH). Thus, according to the present invention, IL-1α and IL-1β are used as mucosal adjuvants to induce antigen-specific lgA (>ten (10) fold enhancement over the lgA response induced in the absence of adjuvant; two to four (2-4) fold enhancement over the lgA response induced when using CT as an adjuvant) that is detectable at a site removed from the site of immunization. More particularly, after intranasal immunization in a mammalian test subject, antigen-specific lgA were detected in secretions of the female reproductive tract. No toxic effects, such as anaphylaxis, were noticed with the use of IL-1 (α and β) as a mucosal adjuvant. Such an adjuvant is useful for vaccine-mediated protection against a variety of pathogens. More particularly, such an adjuvant is useful for vaccine-mediated protection against pathogens that infect via the mucosal surfaces of the host, such as HIV.

Suitable antigens which can be used in the antigen-adjuvant compositions of the present invention include soluble antigens, such as proteins, peptides, hormones and glycoproteins. Antigens of particular interest are viral, fungal, parasite or bacterial antigens, allergens, auto-immunity related antigens, or tumor-associated antigens. The antigens can be obtained from natural sources or they can be produced by recombinant DNA technology or by other artificial means. Particular antigens contemplated for use according to the present invention are set forth in the Examples presented below.

Among the bacterial antigens of interest are those associated with the human and animal bacterial pathogens including, but not limited to for example, typable and nontypable Haemophilus influenzae, Escherichia coli, Neisseria meningitidis, Streptococcus pneumoniae, Streptococcus pyogenes, Branhamelia catarrhalis, Vibdio cholerae, Corynebacteria diphtheriae, Neisseria gonorrhoeae, Bordetelia pertussis, Pseudomonas aeruginosa, Staphylococcus aureus, Klebsiella pneumoniae and Clostridium tetani. Some specific bacterial antigens include bacterial surface and outer membrane proteins (e.g. from Haemophilus influenzae, Neisseria meningitidis, Neisseria gononrhoeae or Branhamella catarrhalis) and bacterial surface proteins (e.g. the M protein from Streptococcus pyogenes).

Viral antigens from pathogenic viruses include but are not limited to, HIV (types I and II), human T-cell leukemia virus (types I, II and III), RSV, hepatitis A, hepatitis B, hepatitis C, non-A and non-B hepatitis virus, herpes simplex virus (types I and II), cytomegalovirus, influenza virus, parainfluenza virus, poliovirus, rotavirus, coronavirus, rubella virus, measles virus, varicella, Epstein Barr virus, adenovirus, papilloma virus and yellow fever virus.

Several specific viral antigens of these pathogenic viruses include the F protein (described in W089/02935 by Paradiso et al.) and the N and G proteins of RSV; VP4 (previously known as VP3); VP6 and VP7 polypeptides of rotavirus; envelope glycoproteins of HIV; and the surface and presurface antigens of hepatitis B and herpes glycoproteins B and D.

Fungal antigen that can be those derived from fungi including but not limited to Candida spp. (e.g., albicans), Cryptococcus spp. (e.g., neoformans), Blastomyces spp. (e.g., dermatitidis), Histoplasma spp. (e.g., capsulatum), Coccidroides spp. (e.g., immitis), Paracoccidroides spp. (e.g., brasiliensis) and Aspergillus spp. Examples of parasite antigens include, but are not limited to, Plasmodium spp., Eimeria spp., Schistosoma spp., Trypanosoma spp., Babesia spp., Leishmania spp., Cryptosporidia spp., Toxoplasma spp. and Pneumocystis spp.

Also of interest are various antigens associated with auto-immune diseases, such as rheumatoid arthritis and lupus erythematosus.

Other applications may also include the elicitation of an immune response to stimulate or inhibit the stability or interaction of cellular modifiers, including hormones with their corresponding receptors or binding components. In this fashion, the immune response can be used to inhibit/enhance growth, reproduction, differentiation, and overall performance.

It is to be understood from the above discussion, that the use of the term antigen is meant to imply either the whole antigen or one of its determinants. The foregoing list of antigens is for exemplary purposes only. Additional antigens which can be used in the antigen-adjuvant compositions of the present invention are readily ascertained by one skilled in the art. Further, the antigen-adjuvant formulations of the present invention are stable for a period of time sufficient to allow the manufacture, shipment and storage of the vaccine formulations.

The following Examples have been included to illustrate preferred modes of the invention. Certain aspects of the following Examples are described in terms of techniques and procedures found or contemplated by the present inventors to work well in the practice of the invention. These Examples are exemplified through the use of standard laboratory practices of the inventors. In light of the present disclosure and the general level of skill in the art, those of skill will appreciate that the following Examples are intended to be exemplary only and that numerous changes, modifications and alterations can be employed without departing from the spirit and-scope of the invention.

EXAMPLES Example 1

IL-1α and IL-1β As Mucosal Adiuvants

MATERIALS AND METHODS

Animals

Female BALB/c and C57BL/6 mice, 16-18 grams, were purchased from Frederick Cancer Research and Developmental Center, National Cancer Institute, Frederick, Md. Animals were housed in filter top cages and provided food and water ad libitum. All procedures for use and care of mice were approved by Duke University's Institutional Animal Care and Use Committee.

Immunization

Mice were intranasally immunized as previously described, Staats et al., J Immunol 157:462 (1996); Porgador et al., J Immunol 158:834 (1997); Staats et al., AIDS Research & Human Retroviruses 13:945 (1997). Briefly, mice (3-4 mice per group) were intranasally immunized with the indicated concentration (Table 2) of ovalbumin (#A-5503 SIGMA, St. Louis, Mo.) or tetanus toxoid (graciously provided by Dr. John Eldridge, Wyeth-Lederle Vaccines and Pediatrics) and the indicated adjuvant in a total volume of 15 μl (7.5 μl/nostril). The mucosal adjuvant cholera toxin was obtained from List Biological Laboratories, Inc. (Campbell, Calif.). Recombinant human IL-lα and IL-1β was obtained from the National Cancer Institute Biological Resources Branch, Division of Cancer Treatment, FCRDC (Frederick, Md). Antigen preparations were diluted to the appropriate concentration in sterile distilled water and 7.5 μl of the antigen mixture was introduced into each nostril while mice were under isoflurane anesthesia (IsoFlo, USP; SOLVAY Animal Health, Inc., Mendota Heights, Minn.).

Sample Collection

Blood was collected from the retroorbital plexus using a heparinized Natelson capillary tube (Baxter Healthcare Corporation, McGaw Park, Ill.) while mice were under isoflurane anesthesia. Vaginal wash samples were collected by washing the vaginal cavity with 100 μl sterile PBS while mice were anesthetized with isoflurane. This procedure resulted in an approximate ten (10) fold dilution of vaginal samples, Staats et al., J Immunol 157:462 (1996). All samples were stored at −20° C until assayed for antigen-specific antibodies.

ELISA

Enzyme-linked immunosorbent assay (ELISA) was used to determine the presence of antigen-specific antibodies in serum and vaginal wash samples. The ELISA assay was performed as previously reported, Staats et al., J Immunol 157:462 (1996); Staats et al., AIDS Research & Human Retroviruses 13:945 (1997), except that ELISA plates were coated with ovalbumin or tetanus toxoid at 5 μg/ml. The end-point titer represents the reciprocal dilution of the last sample whose optical density is at least two (2)-fold higher than the optical density of a corresponding naive sample. Due to the small vaginal lavage sample sizes, vaginal lgG and lgA responses are reported as end-point ELISA titers instead of standardizing based on total lgG and lgA concentrations, Staats et al., J Immunol 157:462 (1996); Staats et al., AIDS Research & Human Retroviruses 13:945 (1997).

Cell Isolation and Proliferation Assay

Spleens (SP) were aseptically removed and single cell suspensions were produced by cutting the spleen into small pieces (˜5 mm×5 mm) and expressing the cells from the splenic capsule with the sterile end of a 5 cc syringe plunger. Red blood cells were removed by centrifugation over CAPPEL™ Lymphocyte Separation Media (ICN Biomedical, Aurora, Ohio). Cells were adjusted to 2 ×10⁶ cells/ml in complete T cell media (RPMI 1640, 10% FBS, HEPES, Pen/Strep, 2-ME). To an equal volume of cells was added an equal volume of complete T cell media or media containing 0.2 μg/ml of the appropriate antigen (ovalbumin or tetanus toxoid) to give a final cell density of 1×10⁶ cells/ml and antigen at 0.1 μg/ml. Cells (100 ml) were added to round-bottom 96-well microtiter plates in triplicate and incubated in a 37° C., 10% CO₂ in air, humidified environment for five days. Four-six (4-6) hours before harvesting, 0.5 μCi [³H]-thymidine (NEN Research Products, Boston, Mass.) was added to each well. Cells were harvested onto glass filters using a PHD™ sample harvester (Cambridge Technology Inc., Watertown, Mass.). Incorporation was determined by placing the filters in SCINTIVERSE BD™ scintillation fluid (FISHER, Pittsburgh, Pa.) and counting with a 2000CA TRI-CARB@D™ liquid scintillation analyzer(Packard, Downers Grove, Ill.).

Delayed Type Hypersensitivity (DTH)

For the measurement of DTH responses, an ear swelling assay was employed as previously described, Staats et al., J Immunol 157:462 (1996); Staats et al., AIDS Research & Human Retroviruses 13:945 (1997). Briefly, 25 μg of immunization antigen was injected into the right ear in 10 μl sterile PBS while 10 μl sterile PBS was injected into the left ear as control. Ear swelling was measured 24-48 hours after injection with a dial thickness gauge (Mitutoyo, Japan, code #7326). Antigen-specific ear swelling was calculated by subtracting the ear swelling of the PBS injected ear from the swelling of the antigen-injected ear.

Statistical Analysis

Statistical significance was determined using ANOVA™ with comparison of multiple means using Bonferroni (Dunn) T tests, Sidak T tests, and Tukey's Studentized Range Test on SAS™ software (SAS Institute, Cary, N.C.). A difference was considered significantly different if two of three tests indicated a significant difference. The level of significance used was 0.05.

Results

IL-lα and IL-1β enhance serum antigen-specific lgG responses when intranasally administered with soluble protein antigens. To determine if IL-lα or IL-1β, possessed mucosal adjuvant activity, BALB/c or C57BL/6 mice were intranasally immunized with antigen alone or antigen in the presence of CT, IL-lα or IL-1β (Table 2). In experiment 1, BALB/c mice were intranasally immunized with 100 μg of ovalbumin on day 0, 14, and 28 in the absence of adjuvants or in the presence of 1 μg of CT, 4 μg IL-lα, or 4 μg IL-1β administered with all immunizations or with the first immunization only (Table 2). Both IL-lα and IL-1β were able to serve as mucosal adjuvants when intranasally administered with ovalbumin with all immunizations (×3) orwith the first immunization only (×1) (p<0.05 compared to no adjuvant control). When co-administered with all three immunizations, the day 42 serum anti-ovalbumin lgG titer for the IL-1α, IL-1β, and CT groups was 1:262,144, 1:104,031 and 1:13,004, respectively (FIG. 1, #1).

IL-lα and IL-1β were also effective adjuvants when administered with the first immunization only. Such administration resulted in serum anti-ovalbumin lgG titers of 1:26,008 and 1:13,004, respectively. Anti-ovalbumin lgG titers were less than 1:100 in the sera collected from mice immunized with no adjuvant or with CT administered with the first immunization only (FIG. 1, #1).

To determine if IL-lα and/or IL-1β exhibited mucosal adjuvant activity when co-administered with a more relevant vaccine antigen, C57BL/6 (Exp. #2) or BALB/c (Exp. #3) mice were intranasally immunized with 50 μg tetanus toxoid (TT) alone or in the presence of adjuvants (Table 2). To comply with other published mucosal immunization protocols, Xu-Amano et al., Joumal of Expermental Medicine, 178:1309 (1993); Marinaro et al., J Immunol 155:4621 (1995), mice were immunized on day 0, 7, and 14 for experiments #2 and #3 (Table 2).

IL-lα and IL-1β were effective mucosal adjuvants when intranasally administered with 50 μg TT on day 0, 7, and 14 in both C57BL/6 (Exp. #2) and BALB/c (Exp. #3) mice (p<0.05 as compared to no adjuvant control). When administered with all three immunizations (×3), day 21 serum anti-TT titers for IL-lα and IL-1β groups were 1:155,872 and 1:208,064 for C57BL/6 mice, respectively, and 1:165,140 and 1:208,064, respectively, for BALB/c mice (FIG. 1, #2 and #3). IL-lα also exhibited significant adjuvant activity when intranasally administered to BALB/c mice with TT on day 0 only (p<0.05 as compared to no adjuvant control). Within the same experiment, there were no statistically significant differences between any of the CT, IL-lα or IL-1β adjuvant groups.

Antigen-specific lgG subclass end-point titers were measured to compare the antigen-specific lgG subclass responses induced by IL-lα and IL-1β to those induced by CT. The antigen-specific lgG subclass profiles associated with the use of IL-lα or IL-1β as a mucosal adjuvant were comparable to those induced by the use of CT as a mucosal adjuvant (Table 3).

IL-lα and IL-1β induce mucosal lgA responses when used as a mucosal adjuvant. Vaginal lavage samples were monitored for the presence of antigen-specific lgG and lgA to determine if IL-lα or IL-1β could enhance the production of antigen-specific lgA responses when used as a mucosal vaccine adjuvant. In all experiments, IL-lα and IL-1β were as effective as CT for their ability to induce the production of antigen-specific mucosal lgA and lgG responses (FIG. 2). In experiment #1, when the adjuvants were used with all three immunizations, the day 42 vaginal anti-ovalbumin lgA titers for the IL-lα and IL-1β groups were 1:32 and 1:128, respectively, compared to an undetectable anti-ovalbumin lgA response in the CT group (FIG. 2, #1). Even when used with the first immunization only, IL-1α and IL-1β induced anti-ovalbumin lgA responses that were detectable in vaginal lavage samples (FIG. 2, #1). In experiments #2 and #3, the use of IL-lα and IL-1β with all immunizations (×3) consistently induced antigen-specific vaginal lgA titers that were two to eight (2-8)-fold higher than those induced by CT (FIG. 2, #2 and #3). When administered with TT for the first immunization only, IL-lα (Exp. #3) and IL-1β (Exp. #2 and #3) induced the production of anti-TT vaginal lgA responses.

IL-lα and IL-1β induce cell-mediated immune responses when used as a mucosal adjuvant. Ear-swelling delayed-type hypersensitivity (DTH) responses were used as in indicator of in vivo cell-mediated immune responses after intranasal immunization with soluble protein antigens alone or in the presence of CT, IL-lα or IL-1β. When intranasally administered with ovalbumin for all three immunizations (Exp. #1), IL-lα and IL-1β induced DTH ear-swelling responses (114+8.9, 106+7.6 DTH units, respectively) that were significantly greater than those induced by any other groups (p<0.05, FIG. 3). In subsequent studies, IL-lα (×3, Exp. #3) and IL-1β (x3, Exp. #2) induced DTH ear-swelling responses that were significantly greater than those induced by immunization in the absence of adjuvant (p<0.05) and comparable to those induced by CT. The use of IL-1 with the first immunization only did not induce significantly elevated DTH ear-swelling responses. Antigen-induced lymphocyte proliferative responses were also monitored as an indicator of antigen-specific, cell-mediated immune responses. Both IL-lα and IL-1β induced lymphocyte proliferative responses comparable to those induced by CT in all three experiments (FIG. 4).

Discussion

Results from this Example indicate that IL-1α and IL-1β are able to serve as mucosal adjuvants when intranasally administered with soluble protein antigens. IL-1α and IL-1β were as effective as CT for the induction of antigen-specific serum lgG, vaginal lgA, as well as in vivo and in vitro cell-mediated immune responses. Although numerous reports have indicated that IL-1 is able to serve as an adjuvant for the induction of antigen-specific immune responses (See e.g., Lin et al., Clinical Infectious Diseases 21:1439 (1995); Hakim et al., Journal of Immunology 157:5503 (1996)), the present invention provides the first demonstration of mucosal adjuvant activity for IL-1 when intranasally administered with soluble protein antigens.

IL-1α and IL-1β are proinflammatory cytokines produced by many cell types including macrophages, PBMC, fibroblasts, and intestinal epithelial cell lines. (See e.g., Bromander et al., Journal of Immunology 146:2908 (1991); Bromander et al., Scandinavian Journal of Immunology 37:452 (1993); Dinarello, C.A., Blood 87:2095 (1996); Dinarello, C.A., Faseb J8:1314 (1994); Dinarello, C.A., Chemical Immunology 51:1 (1992); Krakauer, T., Cellular Immunology 172:224 (1996).) IL-lα and IL-1β utilize the same cell-surface receptors, type I and type II, although only the type I IL-1 receptor transduces a signal in response to ligation of the receptor with IL-1. (See e.g., Dinarello, C.A., Blood 87:2095 (1996); O'Neill, L.A.J., Biochimica et Biophysica Acta 1266:31 (1995); Bankers-Fulbright et al., Life Sciences 59:61(1996).) IL-1induces the gene expression of itself as well as a large number of other proteins including IL-2, IL-3, IL-4, IL-5, IL-6, IL-7, IL-8, IL-12, TGF-β3, TNFα, TNFβ, GM-CSF, G-CSF, M-CSF, and the IL-2 receptor. (See e.g., Dinarello, C.A., Blood 87:2095 (1996); Krakauer, T., Cellular Immunology 172:224(1996).)

Because of its ability to induce the production of cytokines involved in the induction of immune responses, the potential of IL-1 as a vaccine adjuvant is apparent. However, IL-1 has been extensively studied in humans and found to be extremely toxic after intravenous administration. (See e.g., Dinarello, C.A., Chemical Immunology 51:1 (1992); Rinehart et al., Cancer Investigation 15:403 (1997); Verschraegen et al., European Journal of Cancer, 32A:1609(1996).) With both IL-lα and IL-1β, the predominant side effect observed was fever, chills, hypotension and nausea. In such studies, IL-1 was administered by the intravenous (IV) route and was administered daily for 4 to 14 days.

In sharp contrast, in the methods of the present invention, no toxic side effects (ruffled fur, weight loss) were observed at any time. Additionally, IL-1α and IL-1β were administered locally and were effective adjuvants when administered at weekly (Exp. #2, #3) or biweekly intervals (Exp. #1). In some cases, IL-1 was an effective adjuvant when administered with only the first immunization in a series of immunizations. Because IL-1 stimulation of mucosal epithelial cells down-regulates expression of the type I IL-1 receptor, the inflammatory activity of IL-1 used as a mucosal adjuvant is minimized. (See e.g., McGee et al., Cellular Immunology 168:276(1996).)

IL-1α and IL-1β are superior to CT and related molecules as mucosal adjuvants because they are “self” proteins. Although CT is a potent mucosal adjuvant, the fact that it is very immunogenic, in addition to being toxic, diminishes its effectiveness when repeatedly used as a mucosal adjuvant. Indeed, pre-existing immunity to CT reduces its effectiveness as a mucosal adjuvant. (See e.g., Lyce et al., Scand J Immunol 33:691 (1991); Wu et al., Vaccine 12:215 (1994).) Despite having reduced toxicity in the presence of adjuvant activity, mutant CT molecules maintain their immunogenicity, which also prevents them from being repeatedly used as mucosal adjuvants in humans. (See e.g., Douce et al., Infection & Immunity 65:2821 (1997); Fontana et al., Infection & Immunity 63:2356 (1995); de Haan et al., Infection and Immunity 64:5413 (1996).)

In contrast to CT, IL-1α and IL-1β are “self” proteins and therefore substantially non-immunogenic. Stated differently, IL-1α and IL-1β are substantially less immunogenic than CT and mutant CT adjuvants. Since species-specific cytokines are used as adjuvants, the host will not recognize the cytokine as a foreign substance. Therefore, the host will not mount an immune response against the cytokine and “pre-existing” immunity does not become a problem. Thus, the cytokines may be used repeated without the concern that “anti-cytokine” antibodies will neutralize their adjuvant activity and reduce their effectiveness as mucosal adjuvants.

The correlates of protective immunity for mucosally transmitted HIV are not known. However, both HIV-specific CTL and mucosal lgA appear to be important. (See e.g., Mazzoli et al., Nature Medicine 3:1250 (1997); De Maria et al., Journal of Infectious Diseases 170:1296(1994).) Heretofore, HIV mucosal vaccine studies in humans have been hampered by the absence of safe and effective mucosal vaccine adjuvants. The results observed through the use of the method of the present invention indicate that 1) IL-1α and IL-1β are effective mucosal adjuvants for the induction of systemic and mucosal immune responses and 2) cytokines are biologically active when intranasally administered. The use of cytokines as mucosal adjuvants is thus useful for the induction of systemic and mucosal immune responses in humans.

TABLE 1 Table 1. Literature review on the effects of mucosal adjuvants and cytokines on cytokine production and APC activity by intestinal epithelial and macrophage cell lines, PBMC, sIgA B cells, and freshly isolated intestinal epithelial cells. APC activity was determined in alloantigen presentation systems. Cell Line IgA APC (type) Stimulus IL-1 IL-6 IL-8 Production Activity Reference IEC-6 CT ↑ McGee et (epithelial) CT-B ←→ al. (1993) IL-1β ↑↑ TGF-β1 ↑ TNFα ↑↑ TGF-β1 + IL-1β ↑↑↑ TNFα + IL-1β + TGF-β1 ↑↑↑ CT + IL-1β ↑↑↑ CT + TNF-α ↑↑↑ IEC-17 CT ↑↑ ↑ Bromander (epithelial) et al. (1993) Caco-2 IL-1β ↑↑↑ ↑↑ Parikh et al. (epithelial) (1997) HT-29 IL-1β ↑↑ Eckmann et (epithelial) al. (1993) P388D1 CT ↑↑ ↑ Bromander (MF) CT + anti-IL-1α ←→ ←→ et al., (1991) PBMC CT ↑↑↑ ↑↑ ←→ Krakauer, T. (1996) SIgA B CT ↑ Kin et al., cells CT + anti-TGF-β ←→ (1998) TGF-β1 ↑↑ TGF-β1 + anti-TGF-β ←→ Freshly IL-1β 1FN-δ TNF-α ↑ Panja et al. Isolated ←→ (1995) IEC ←→ Symbol legend: ←→ = no change over unstimulated control cells; ↑ = 210 fold enhancement over unstimulated controls; ↑↑ = 10-100 fold enhancement over unstimulated controls; ↑↑↑ => 100 fold enhancement over unstimulated controls.

TABLE 2 Table 2. Immunization protocols to evaluate the mucosal adjuvant activity of IL-1α and IL-1β. There were three to four (3-4) mice per group, per experiment. For technical details concerning the immunization, please see Materials and Methods. Immunization Adjuvant Groups Immunogen Schedule Adjuvant Schedule Exp. #1 (BALB/c) None Ovalbumin (100 μg) Day 0, 14, 28 None None CT × 3 Ovalbumin (100 μg) Day 0, 14, 28 CT (1 μg) Day 0, 14, 28 CT × 1 Ovalbumin (100 μg) Day 0, 14, 28 CT (1 μg) Day 0 IL-1α × 3 IL-1α × Ovalbumin (100 μg) Day 0, 14, 28 IL-1α (4 μg) Day 0, 14, 28 1 IL-1β × 3 IL-1β × Ovalbumin (100 μg) Day 0, 14, 28 IL-1α (4 μg) Day 0 1 Ovalbumin (100 μg) Day 0, 14, 28 IL-1β (4 μg) Day 0, 14, 28 Ovalbumin (100 μg) Day 0, 14, 28 IL-1β (4 μg) Day 0 Exp. #2 (BALB/c) Exp. #3 (C57BL/6) None Tetanus toxoid (50 μg) Day 0, 7, 14 None None CT × 3 Tetanus toxoid (50 μg) Day 0, 7, 14 CT (1 μg) Day 0, 7, 14 CT × 1 Tetanus toxoid (50 μg) Day 0, 7, 14 CT (1 μg) Day 0 IL-1α × 3 Tetanus toxoid (50 μg) Day 0, 7, 14 IL-1α (4 μg) Day 0, 7, 14 IL-1α × 1 Tetanus toxoid (50 μg) Day 0, 7, 14 IL-1α (4 μg) Day 0 IL-1β × 3 Tetanus toxoid (50 μg) Day 0, 7, 14 IL-1β (4 μg) Day 0, 7, 14 IL-1β × 1 Tetanus toxoid (50 μg) Day 0, 7, 14 IL-1β (4 μg) Day 0

TABLE 3 Table 3. Antigen-specific serum IgG subclass profiles after intranasal immunization as described in Materials and Methods and Table 2. Experiment #1 represent day 35 responses, while results for Experiments #2 and #3 represent day 21 responses. Sera from three to four (3-4) mice per group, per experiment was pooled and assayed for antigen-specific IgG1, IgG2a, IgG2b, or IgG3 end-point titers. Antigen-Specific End-Point Titer Group IgG1 IgG2a IgG2b IgG3 Experiment #1 None <64 <64 <64 <64 CT × 3 32,768 <64 <64 <64 CT × 1 <64 <64 <64 <64 IL-1α × 3 524,288 256 4,096 <64 IL-1α × 1 65,536 <64 <64 <64 IL-1β × 3 131,072 8,182 8,192 <64 IL-1β × 1 32,768 <64 <64 <64 Experiment #2 None 1,024 <64 <64 <64 CT × 3 65,536 512 16,384 <64 CT × 1 65,536 <64 1,024 <64 IL-1α × 3 131,072 <64 8,192 512 IL-1α × 1 32,768 <64 512 <64 IL-1β × 3 131,072 <64 8,192 <64 IL-1β × 1 65,536 <64 4,096 <64 Experiment #3 None 8,192 <64 512 <64 CT × 3 262,144 4,096 8,192 256 CT × 1 262,144 4,096 8,192 <64 IL-1α × 3 262,144 4,096 8,192 <64 IL-1α × 1 131,072 1,024 8,192 <64 IL-1β × 3 262,144 8,192 8,192 <64 IL-1β × 1 32,768 512 2,048 <64

TABLE 4 Ability of IL-1α and IL-1β to serve as mucosal adjuvants when intranasally administered with ovalbumin (Experiment #1) or tetanus toxoid (Experiments #2 and #3) Serum Antigen-Specific IgG Vaginal Antigen-Specific Antigen-Specific Splenocyte Responses IgA Responses Proliferative Responses Fold Fold Fold Fold Lymphocyte Fold Fold Increase Increase Increase Increase Proliferative Increase Increase over over over over Responses at over over “No” “CT” IgA “No” “CT” 0.1 μg/ml “No” “CT” Exp Adjuvant IgG Titer adjuvant adjuvant Titer adjuvant adjuvant antigen adjuvant adjuvant #1 None <1:64 <1:4 Not determined. CT × 3   1:13,004 >203 <1:4 None IL-1α × 1   1:26,008 >406 2   1:4 >1 >1 IL-1α × 3   1:262,154 >4,096 20   1:32 >8 >8 IL-1β × 1   1:23,004 >203 None   1:32 >8 >8 IL-1β × 3   1:104,032 >1,625 8   1:128 >32 >32 #2 None   1:256 <1:4 310 CT × 3   1:104,032 406   1:64 >16 11908 IL-1α × 1   1:20,643 80 None <1:4 None None 338 IL-1α × 3   1:155,872 608 1.49   1:512 >128 8 10638 IL-1β × 1   1:65,536 256 None   1:128 >32 2 704 IL-1β × 3   1:208,064 812 2   1:256 >64 4 7931 #3 None   1:2,048   1:4 757 CT × 3   1:832,255 406 None   1:256 64 15108 20 IL-1α × 1   1:26,008 12 None   1:256 64 None 10140 13 None IL-1α × 3   1:165,150 80 None   1:512 128 2 21556 28 1.4 IL-1β × 1   1:13,004 6 None   1:128 32 None 5414 7 None IL-1β × 3   1:208,064 101 None   1:512 128 2 15671 20 None

In Table 4, lgG and lgA titers represent the final dilution of sample (serum or vaginal lavage, respectively) that gives a positive response in an antigen-specific ELISA assay. Lymphocyte proliferative responses represent “counts per minute” of splenocytes stimulated in vitro with 0.1 μg/ml of immunizing antigen and cultured for 5 days.

For each category (serum lgG, vaginal lgA, or splenocyte proliferative responses), fold increase over no adjuvant was calculated by dividing the response induced in the presence of adjuvant by the response induced in the absence of adjuvant. To calculate fold increase over CT positive control, the response induced in the presence of IL-lα or IL-1β was divided by the response induced when using CT as a positive control.

In Table 4, mice were immunized on day 0, 14, and 28 with 100 μg ovalbumin for Experiment #1 and on day 0, 7, and 14 with 50 μg tetanus toxoid for Experiments #2 and #3. CT was employed as a positive control mucosal adjuvant and was administered with each immunization (×3) at a dose of 1 μg. IL-1α and IL-1β were tested as mucosal adjuvants at a dose of 4 μg. IL-1αor IL-1β was administered with the first immunization only (×1) or with all three immunizations (×3).

Table 4 indicates that both IL-1α and IL-1β exhibit mucosal adjuvant activity when intranasally administered with soluble protein antigens as determined by their ability to enhance the induction of antigen-specific serum lgG, vaginal lgA, and splenocyte proliferative responses (as compared to responses induced in the absence of adjuvants). In some cases, IL-1α and IL-1β induced antigen-specific responses that were superior to those induced by the positive control adjuvant, CT.

Example 2

Synthetic IL-1B Peptide as a Mucosal Adiuvant

Recombinant interleukin 1β and the synthetic IL-1β peptide 163-171 each possess mucosal adjuvant activity in accordance with the methods of the present invention. In this Example, BALB/c female mice were purchased from Charles River Laboratories and divided into groups of three to four (3-4) mice per group. All mice were intranasally immunized with 100 μg ovalbumin in distilled water in a total volume of 15 μL (7.5 μL per nostril). A total of five groups was used to test the adjuvant activity of IL-1α, IL-1β, and the IL-1β peptide as compared to the adjuvant activity of cholera toxin (Table 4). Mice were immunized a total of three times a week at two week intervals (day 0, day 14, and day 28). Serum was collected at day 35 and assayed for the presence of anti-ovalbumin lgG with ELISA, as described above. DTH responses were measured on day 42 by injecting 10 μL of sterile PBS into the left ear pinna and 10 μL of sterile PBS containing 30 μg ovalbumin into the right ear. Ear-swelling was measured 24 hours later; antigen-specific DTH responses were calculated by subtracting the PBS (left) ear-swelling from the ovalbumin (right) ear-swelling. Ear-swelling units correspond to 1×10⁴ inches.

TABLE 5 Peak Serum anti-ovalbumin Anti-ovalbumin Ovalbumin (μg) Adjuvant (μg) serum IgG titer DTH response 100 none <1:100      4.24 ± 8.5 100 cholera toxin (1) 1:3,250  36.7 ± 8.1 100 IL-1α (4) 1:131,072 114.7 ± 8.9  100 IL-1β (4) 1:65,536   106 ± 7.6 100 IL-1β peptide (225) 1:2,580    16 ± 1.4

For this Example, IL-lα and IL-1β were effective when intranasally administered with antigen at dosages of 200 μg/kg (high dose) and 67 μg/kg (low dose). The 163-171 IL-1β peptide was used at dosages of 11.25 mg/kg.

Example 3

Use of IL-15 and GM-CSF as Mucosal Adiuvants

In accordance with the methods of the present invention, IL-15 or GM-CSF were admixed with 100 μg C4-V4 Roman IIIB HIV peptide vaccine (contains T-helper, V-cell and CTL epitopes) and delivered intranasally to BALB/c mice on day 0, 7, 14, and 21. Control mice received peptide only (negative control) or peptide and cholera toxin (positive control). Serum was collected on day 28 and tested for the presence of anti-C4-V3 IIIB lgG. Both IL-15 and GM-CSF served as mucosal adjuvants as indicated by the detection of antigen-specific serum lgG responses of 1:16,384 for both IL-15 and GM-CSF groups as compared to undetectable serum lgG responses in the negative control group and titer of 1:41,285 in the positive control group.

To determine if IL-15 or GM-CSF could enhance the immune response induced by intranasal immunization with peptide and CT, mice were immunized with peptide, CT and IL-15; or peptide, CT, and GM-CSF. The combination of CT and GM-CSF was not superior to GM-CSF alone or CT alone. However, the combination of CT and IL-15 induced a serum anti-peptide lgG titer ten (10)-fold better than that induced by IL-15 alone and four (4) times higher than that induced by peptide and CT.

These results indicate that 1) IL-15 and GM-CSF are active when delivered intranasally and 2) IL-15 and GM-CSF exhibit mucosal adjuvant activity when intranasally delivered with peptide vaccines.

Immunization Schedule

100 μg C4-V3 IIIB intranasally to BALB/c mice on day 0, 7, 14, and 21 alone or with:

CT (1 μg) CT and IL-15 (1 μg each)

IL-15 (1 μg) OR

GM-CSF (1 μg) CT and GM-CSF (1 μg each)

TABLE 6 Mucosal Adjuvant Activity of IL-15 and GM-CSF Intranasally Administered with C4-V3 IIIB HIV Peptide Serum IgG End-point Titer Immunization Group (reciprocal) C4-V3 IIIB  <100  C4-V3 IIIB + CT 41,285 C4-V3 IIIB + IL-15 16,384 C4-V3 IIIB + CT + IL-15 165,140  C4-V3 IIIB + GM-CSF 16,384 C4-V3 IIIB + CT + GM-CSF  8,192

Example 4

Combinations of Substantially Non-Toxic Biologically Active Adiuvants in Mucosal Immunization

As described above, the induction of antigen-specific mucosal immunity is beneficial for the prevention of infections due to pathogenic microorganisms that initiate infection at the mucosal surfaces of the host. Additionally, mucosal immune responses may be beneficial forthe treatment of malignant tumors that metastasize to mucosal tissues. To induce mucosal immune responses, antigens are delivered via a mucosal route in accordance with the methods of the present invention. In this Example, the use of cytokines/chemokines/growth factors/apoptosis inhibitors in selected combinations as adjuvants is described for enhancing the induction of antigen-specific systemic and mucosal immune responses when administered along with a vaccine antigen via the intranasal or other mucosal route (e.g., genital, rectal, or oral).

In accordance with the present invention, vaccine-induced immunity is enhanced by the use of biologically active molecules that:

1. Promote angiogenesis at the site of immunization and therefore enhance the blood flow to the site of immunization. Increased blood flow produces an increased number of lymphocytes at the site of immunization that may thus be available to participate in the induction of vaccine-specific immune responses.

2. Promote chemotaxis of dendritic cells and/or subsets of lymphocytes to the site of immunization. Increased numbers of local dendritic cells may thus result in increased antigen presentation and enhanced immunity. Increasing the numbers of specific lymphocyte subsets at the site of immunization skews the immune response towards T-helper type 1 (Th1) or T-helper type 2 (Th2). This mechanism is thus an excellent candidate through which to target vaccines to produce primarily antibody or cellular immune responses.

3. Prevent or inhibit apoptosis of antigen-specific lymphocytes. This leads to an increased number of vaccine-specific lymphocytes and a qualitatively and quantitatively better immune response.

4. Combinations of agents with the above qualities may be used to enhance the effectiveness of agents used individually (Table 7).

TABLE 7 Group IL-1 Cytokine 1 None None 2 Yes None 3 Yes IL-5 4 Yes IL-6 5 Yes IL-12 6 Yes IL-15 7 Yes TGFβ 8 Yes IFNα 9 Yes GM-CSF 10  Yes Angiogenic Factor(s) 11  Yes Chemotactic Factor(s) 12  Yes Apoptosis Inhibitor(s) 13  Multiple Combinations

The adjuvant molecules described in this Example are administered according to the dosage ranges and schedules described above.

Angiogenic factors

Basic fibroblast growth factor, vascular endothelial growth factor, and hyaluronan fragments. Esser et al., J Cell Biol 140:947 (1998); Arkonac et al., J Biol Chem 273:4400 (1998); Qu et al., Int Arch Allergy Immunol 115:47 (1998).

Chemotactic Factors

LARC (Liver and Activation Regulated Chemokine) see e.g., Hieshima et al., Journal of Biolgocial Chemistry 272:5846 (1997); PARC (Pulmonary and Activation Regulated Chemokine) see e.g., Hieshima et al., Journal of Immunology 159:1140 (1997); MDC (macrophage derived chemokine) see e.g., Godiska et al., Journal of Expenmental Medicine 185:1595 (1997); TARC (Thymus and Activation Regulated Chemokine) see e.g., Imai et al., Journal of Biological Chemistry 271:21514 (1996); SLC (Secondary Lymphoid-Tissue Chemokine) see e.g., Nagira et al., Journal of Biological Chemistry 272:19518 (1997); Fractalkine (FKN) see e.g., Imai et al., Cell 91:521 (1997).

Chemokines that attract dendritic cells to a site of immunization are adjuvant candidates. Immature CCR6+ dendritic cells (iDC) which are attracted by LARC (Liver and Activation Regulated Chemokine) are highly phagocytic and uptake antigen well for later presentation to T cells. GM-CSF and other cytokines like TNF induce DC maturation and improved antigen presentation by DC. Thus, LARC alone, or in combination with GM-CSF or other cytokines, is an excellent adjuvant candidate.

Chemokines skew the immune response towards Th1 vs. Th2 by attracting subsets of T lymphocytes to the site of immunization. MDC (macrophage derived chemokine) and TARC that are highly expressed by dendritic cells and that preferentially attract CCR4+ or CCR8+ Th2 cells may thus skew the response towards antibody production. Chemokines like SLC (Secondary Lymphoid Organ Chemokine) or fractalkine (FKN) which attract naive T lymphocytes or CD8+ T lymphocytes may thus enhance the CTL response.

Inhibitors of Apoptosis

toso, inhibitors of caspase-8 see e.g., Hitoshi et al., Immunity 8:461 (1998).

REFERENCES

The references listed below as well as all references cited in the specification are incorporated herein by reference to the extent that they supplement, explain, provide a background for or teach methodology, techniques and/or compositions employed herein.

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It will be understood that various details of the invention may be changed without departing from the scope of the invention. Furthermore, the foregoing description is for the purpose of illustration only, and not for the purpose of limitation--the invention being defined by the claims. 

1. A method of eliciting an immune response against an antigen in a vertebrate subject, the method comprising: (a) providing an antigen-adjuvant composition comprising the antigen and a cytokine adjuvant selected from the group consisting of IL-1α, IL-12, IL-15, IL-18 and combinations thereof; and (b) administering said antigen-adjuvant composition intramucosally to the vertebrate subject in a manner such that initial contact occurs in mucosal tissue of the vertebrate subject, whereby an immune response is elicited.
 2. The method of claim 1, wherein the antigen-adjuvant composition further comprises IL-lα In combination with at least one other cytokine.
 3. The method of claim 2, wherein the IL-1α is present in the antigen-adjuvant composition in an amount ranging from about 10 to about 1000 micrograms per kilogram body weight of the vertebrate subject.
 4. The method of claim 3, wherein the IL-1α is present in the antigen-adjuvant composition in an amount ranging from about 50 to about 500 micrograms per kilogram body weight of the vertebrate subject.
 5. The method of claim 4, wherein the IL-lα is present in the antigen-adjuvant composition in an amount ranging from about 60 to about 200 micrograms per kilogram body weight of the vertebrate subject.
 6. The method of claim 1, wherein the antigen-adjuvant composition further comprises IL-12 in combination with at least one other cytokine.
 7. The method of claim 1, wherein the antigen-adjuvant composition further comprises IL-15 in combination with at least one other cytokine.
 8. The method of clalm 1, wherein the antigen-adjuvant composition further comprises IL-18 in combination with at least one other cytokine.
 9. The method of claim 1, wherein said manner of administration is selected from the group consisting of intranasal administration, intravaginal administration, and intrarectal administration.
 10. The method of claim 1, wherein the antigen-adjuvant composition is administered once a week over a period of one to three weeks.
 11. The method of claim 1, wherein the antigen-adjuvant composition is administered once every two weeks over a period of two to six weeks.
 12. The method of claim 1, wherein the antigen-adjuvant composition is administered once during a first week, and the method further comprises the step of administering the antigen only once a week over a period of one to two weeks following the first week.
 13. The method of claim 1, wherein the antigen-adjuvant composition is administered once during a first biweekly period, and the method further comprises the step of administering the antigen only once every two weeks over a period of two to four weeks following the first biweekly period.
 14. The method of claim 1, wherein the immune response comprises a systemic immune response.
 15. The method of claim 1, wherein the Immune response comprises a mucosal immune response.
 16. The method of claim 1, wherein the immune response comprises a cell-mediated immune response.
 17. The method of claim 1, wherein the antigen-adjuvant composition further comprises a pharmaceutically acceptable vehicle and the antigen-adjuvant composition is carried therein.
 18. The method of claim 17, wherein the pharmaceutically acceptable vehicle is selected from the group consisting of distilled water and phosphate-buffered saline.
 19. The method of claim 1, wherein the antigen-adjuvant composition is free of mineral adjuvants, preservatives or stabilizers, and wherein the antigen and adjuvant are not conjugated together.
 20. The method of claim 1, wherein the vertebrate subject is a mammal.
 21. The method of claim 20, wherein the mammal is a human.
 22. The method of claim 1 wherein the antigen-adjuvant composition further comprises IL-1α in combination with at least one other cytokine selected from the group consisting of IL-12. IL-15, and IL-18.
 23. The method of cJaim 1, wherein the antigen-adjuvant composition further comprises IL-12 in combination with at least one other cytokine selected from the group consisting of IL-1α IL-15, and IL-18.
 24. The method of claim 23, wherein the antigen-adjuvant composition further comprlses IL-12 in combination with IL-1
 8. 25. The method of claim 1, wherein the antigen-adjuvant composition further comprises IL-16 in combination with at least one other cytokine selected from the group consisting of IL-1α, IL-12, and IL-18.
 26. The method of claim 1, wherein the antigen-adjuvant composition further comprises IL-18 in combination with at least one other cytokine selected from the group consisting of IL-1α, IL-12, and IL-15. 